Behavioural clusters and predictors of performance during recovery from stroke

We examined the patterns and variability of recovery post-stroke in multiple behavioral domains. A large cohort of first time stroke patients with heterogeneous lesions was studied prospectively and longitudinally at 1-2 weeks, 3 months and one year post-injury with structural MRI to measure lesion anatomy and in-depth neuropsychological assessment. Impairment was described at all timepoints by a few clusters of correlated deficits. The time course and magnitude of recovery was similar across domains, with change scores largely proportional to the initial deficit and most recovery occurring within the first three months. Damage to specific white matter tracts produced poorer recovery over several domains: attention and superior longitudinal fasciculus II/III, language and posterior arcuate fasciculus, motor and corticospinal tract. Finally, after accounting for the severity of the initial deficit, language and visual memory recovery/outcome was worse with lower education, while the occurrence of multiple deficits negatively impacted attention recovery

A heat island model for large urban areas and its application to Milano

The study of the urban heat island has been carried out through two new enhanced versions of the UCLM (Urban Canopy Layer Model) model, Landsat/Thematic Mapper data sets and meteorological data collected over a square area 30 km of side including Milan and its hinterland. The urban climate can be described in different summer and winter radiative settings. The input data are divided into two classes: 1) parameters related to urban and rural local properties (albedo and emissivity, vegetation index NDVI, surface roughness length, land cover...); 2) meteorological data related to the general synoptic conditions. The bulk system of the model is made up of four independent equations expressed in terms of four unknowns, i.e., the temperature values at ground level, canopy level and reference level (100 m) and relative humidity within the urban structure. The study area is divided by a regular square mesh of variable dimension (from 30 m to 1500 m); both the input and output data are average cell values. UCLM30 and UCLM60 calculate the temperature excess as well as the turbulent heat exchanges and the heat storage in the urban canopy as a function of the radiative and dynamic forcing. As can be observed in reality, the model shows that in summer the highest urban heating occurs in early morning and after sunset and that, in extreme conditions, the temperature can be up to 8 7C warmer in town than in the nearby rural lands

The Probability of Default of Public Guaranteed Loans: Does the Financial intermediary Matter?

This paper investigates the risk of failure of loans guaranteed by public credit guarantee schemes. We analyse the determinants of the time to default of approximately 15,000 loans guaranteed by the Italian Central Guarantee Fund between 2007 and 2009. Using the Cox proportional hazards model, we test the role of the financial intermediary that requests the guarantee on a firm’s behalf, while distinguishing between banks and mutual guarantee institutions (MGIs) and controlling for a set of variables that characterise each guaranteed loan. The findings confirm that loans are more likely to default when a bank—rather than an MGI—is involved in the guarantee process. Considering some elements (e.g. age, size and sector) that affect opacity among small- and medium-sized enterprises (SMEs), banks seem to perform better than MGIs in screening and monitoring loans requested by firms in the manufacturing sector

Detection of Viral-like Particles by Electron Microscopy of Negatively Stained Extracts from Grapevines

Viral-like particles were detected by electron microscopy of negatively stained extracts from young leaves and roots of grapevines infected with fanleaf virus and purported to be infected with the graft-transmissible agents of Ieafroll, corky bark, fleck, and stem grooving. Preparations were extracted in 0.01 M phosphate buffer (pH 7.0) containing 2.5% nicotine and negatively stained with 2% ammonium molydate. Membrane associated spherical particles were detected in extracts from grapevines that tested positive for fanleaf virus by ELISA and bioassay. Similar membrane associated particles were detected in herbaceous plants inoculated with grapevine extracts. Rigid rod tobacco mosaic virus-like particles were detected in extracts from some grapevines but they were not disease associated. Flexuous rod viral-like particles about 11x800 nm with cross-banding helical substructure similar to closteroviruses were detected in extracts from leafroll infected grapevines

Overlap Statistics of Shallow Boundary Layer Clouds: Comparing Ground-Based Observations with Large-Eddy Simulations

High-resolution ground-based measurements are used to assess the realism of fine-scale numerical simulations of shallow cumulus cloud fields. The overlap statistics of cumuli as produced by large-eddy simulations (LES) are confronted with Cloudnet data sets at the Jülich Observatory for Cloud Evolution. The Cloudnet pixel is small enough to detect cumuliform cloud overlap. Cloud fraction masks are derived for five different cases, using gridded time-height data sets at various temporal and vertical resolutions. The overlap ratio (R), i.e., the ratio between cloud fraction by volume and by area, is studied as a function of the vertical resolution. Good agreement is found between R derived from observations and simulations. An inverse linear function is found to best describe the observed overlap behavior, confirming previous LES results. Simulated and observed decorrelation lengths are smaller (∼300 m) than previously reported (\u3e1 km). A similar diurnal variation in the overlap efficiency is found in observations and simulations

Structural Disconnections Explain Brain Network Dysfunction after Stroke

Stroke causes focal brain lesions that disrupt functional connectivity (FC), a measure of activity synchronization, throughout distributed brain networks. It is often assumed that FC disruptions reflect damage to specific cortical regions. However, an alternative explanation is that they reflect the structural disconnection (SDC) of white matter pathways. Here, we compare these explanations using data from 114 stroke patients. Across multiple analyses, we find that SDC measures outperform focal damage measures, including damage to putative critical cortical regions, for explaining FC disruptions associated with stroke. We also identify a core mode of structure-function covariation that links the severity of interhemispheric SDCs to widespread FC disruptions across patients and that correlates with deficits in multiple behavioral domains. We conclude that a lesion\u27s impact on the structural connectome is what determines its impact on FC and that interhemispheric SDCs may play a particularly important role in mediating FC disruptions after stroke

How good are low back pain guidelines? A critical appraisal of the quality of clinical practice guidelines using the agree II tool

Clinical practice guidelines (CPGs) provide evidence-based recommendations for clinical practice, but their increasing number in the last few years arises possible concerns about their quality. Preliminary results on the methodological quality of CPGs for low back pain management (LBP) are here presented. The results of this review can help researchers and Italian policymakers select and adopt the highest quality Clinical Practice Guidelines (CPGs) for Low Back Pain (LBP) management in the CPG National Systems (Sistema Nazionale Linee Guida)

Decreased integration and information capacity in stroke measured by whole brain models of resting state activity.

While several studies have shown that focal lesions affect the communication between structurally normal regions of the brain, and that these changes may correlate with behavioural deficits, their impact on brain's information processing capacity is currently unknown. Here we test the hypothesis that focal lesions decrease the brain's information processing capacity, of which changes in functional connectivity may be a measurable correlate. To measure processing capacity, we turned to whole brain computational modelling to estimate the integration and segregation of information in brain networks. First, we measured functional connectivity between different brain areas with resting state functional magnetic resonance imaging in healthy subjects (n = 26), and subjects who had suffered a cortical stroke (n = 36). We then used a whole-brain network model that coupled average excitatory activities of local regions via anatomical connectivity. Model parameters were optimized in each healthy or stroke participant to maximize correlation between model and empirical functional connectivity, so that the model's effective connectivity was a veridical representation of healthy or lesioned brain networks. Subsequently, we calculated two model-based measures: 'integration', a graph theoretical measure obtained from functional connectivity, which measures the connectedness of brain networks, and 'information capacity', an information theoretical measure that cannot be obtained empirically, representative of the segregative ability of brain networks to encode distinct stimuli. We found that both measures were decreased in stroke patients, as compared to healthy controls, particularly at the level of resting-state networks. Furthermore, we found that these measures, especially information capacity, correlate with measures of behavioural impairment and the segregation of resting-state networks empirically measured. This study shows that focal lesions affect the brain's ability to represent stimuli and task states, and that information capacity measured through whole brain models is a theory-driven measure of processing capacity that could be used as a biomarker of injury for outcome prediction or target for rehabilitation intervention